joshh44

alright i was cleaning my rims and i had no idea how wide they are so i looked around and i found out that they are 15x8 rims.
im woundering what is the widest tire you can stick on em?
right now the tire size is 235s. i would like to get 275s but im thinking i might need more rim for that. im not to sure so i thought i would ask.

sofakingdom

iTrader: (1)

275 is WAY too much. Yes it will "fit"; yes some people will come on here and tell you they have them and it "works" just fine; but they're wrong. The section width will be almost 11", which will make the tire look like the Goodyear blimp. The tread will be curved, with the weight of the car running on the center, and no weight on the sidewall. All wrong.

You measure wheel width at the inside of the tire bead; meaning, to get an ACCURATE measurement, you'd need to have the tires off. Although, tire stores have those huge plastic "micrometer" things that they put on the outside of the bead, that take about ½" of metal thickness into account, so they're close enough for gov't work usually.

If you have the stock 15" RS wheels on your car, they're actually 7", not 8"; and 235/60-15 is just about the perfect size. I wouldn't go any bigger than that.

If you have some kind of aftermarket wheels on it, and they're really 8", 255/50 would be about right.

You don't want "the widest" tires you can jam onto the wheels.

Sonix

iTrader: (1)

That being said, 275/60/R15 is one of the most common sized tires to put on yer basic muscle car with 15x8 wheels. Look at any second gen camaro and see what you'll find....

Case in point, my car with 1979 Trans-am snowflake 15x8 wheels
https://webdisk.ucalgary.ca/~jmknopp...t,%20may06.jpg
https://webdisk.ucalgary.ca/~jmknopp...th%20tires.jpg

xpndbl3

iTrader: (5)

for an 8" rim you can run a 28" tall tire in 275, for a 26" tire the most I'd put on there would be a 255.

so 275/60 or 255/50 at the widest.

drperformance

iTrader: (5)

I am running 275/50/15 drag radials and they are not like a goodyear blimp, they are fine. But I will say for the most traction they fit best on 9" rims, but do not be afraid to put them on 15x8 rims.

mw66nova

iTrader: (13)

i'm running a 29x9 hoosier on a 15x8, but had a 275/60/15 et street radial for a long long long time. no issues whatsoever. i have a set of 275/50/15's on a set of 15x7's...kinda a backup set "just in case", but i wouldn't run them for long. they do have a lot of sidewall "bulge"

scorchmaster

iTrader: (6)

I got a 295 tire on my 8 inch rim

Sonix

iTrader: (1)

295's in 15" size are kinda rare. Which tire do you have? The BFG drag radial or...? What aspect ratio and what brand?

Stephen

iTrader: (12)

I've run the 295/50 BFGs (street tires, not drag radials) on 16 x 8s...I know a guy currently doing it....And when my 245s go out, I'll be doing the BFGs again.

No traction issues....no "blimp" issues...

Sidewall aspect is the real determining factor. The higher the #, the more width you can get away with.

scorchmaster

iTrader: (6)

it's a dunlop gt qualifier. It's my street tire, and it's ok at best. The size is 295/50-15

Sonix

iTrader: (1)

Hmm. Ok, so you wouldn't recommend it? I think my next rear tires will be drag radials in a 275/60R15. I'll never spin 'em again

joshh44

well there the American Out law II rims.
i would just wided up the rear tires anyways.
i was thinking. with a 275 tire. will it stick out of the fenders?

scorchmaster

iTrader: (6)

use either a 15x8 with 4.5 back spacing or 15x10 with 5.5 spacing and you will be in the fender

joshh44

no there the rims already on my car, they were on it when i bought the car.
and they are 4.5 backspacing. i just mesured it up.

BNBZ28

iTrader: (1)

my car with 275/50/15s mt.
for better pics look at the last pages of my cardomain www.cardomain.com/ride/2197664

CrazyRunninIroc

I am currently running 295 50 16 BFGs on my 89 Iroc. The best thing about them is how they look from behind. Traction and handling are alright, but I was just going for looks on this one, and hit a home run. I would say everybody needs to try a set of these at some point. At about 100 bucks each, they're pretty cheap actually.

joshh44

ill probably check out how much some 275s are. im not going any wider then 235s up front. i need new front tires anyways so ill probably get some thiner tires up front. they seem to rub abit when i do full turns. since the front is lowered 2"
anyways, i checked out the price of the rims that are on the car when i bought it. they are about $120 a rim. i would like to get wider rear rim but there isnt a shop that can make them wider where i live.
i want to get new rims anyways. im looking into getting a set of C6 rims.
but thos would be for crusin and stuff. the 15" tires are for drag racing.
would a 10" wide slick work with the rims i have now?

Stephen

iTrader: (12)

Geez....2 threads going on at the same time, about the same thing....

https://www.thirdgen.org/forums/faq-...tire-size.html

Here's 295s on...
https://www.thirdgen.org/forums/post...51-post22.html

joshh44

GEAH!! must have missed em.

5678TA

i agree with sofa.. i had 275/50-15 mt dr's.. fit fine and worked fine but i could see i wasnt using all the tread.. also had a really hard time hooking up.. too little pressure cupped the middle and too much pressure made a small contact patch.. so at the right pressure, i was still missing some contact area.. never been lower than 1.81 60ft with those.. i was only running a 3.89 gear with that too.. just wouldnt hook how it should..

it looked pretty good but tread marks on the ground tell the tail.. a 255 would be better.. my 275's in this pic you can see the darker/worn part of the tire is the contact patch at full street pressure.. missing about an inch on each side.. people say drag radials hook decently well on the street, but in this form, i had no such traction in first gear or half of second..

joshh44

i think 255 would probably be just right.
im hoping to get some 10" wide rims in the next couple of months and be able to use 275s or 295s.
i dont think ill go any bigger then 295s tho once i get some new rims.
----------
by the way. what is the difference between street tires and drag radials tires? is it just the tread? and are drag radials a softer compond rubber?
i would like to get a pair of drag radials eventually once i get my car finished.
or eather that some slicks. but i slicks on the street is not greatest idea. even if you run into a puddle of water. yikes!

83 Crossfire TA

iTrader: (2)

This is sort of a repeated discussion that is getting a bit old… quick summary of correct answers:

Width of a tire rim is the distance between bead seats. If you measure the whole width of the rim, the actual “rim width” will be as much as 1” smaller. Stock f-body 15” rims are 7” wide

What rim is wide enough for a tire depends on tire construction, aspect ratio and intended use. Just because you want a minimum of a 8.5 or 9” or wider rim for a 275/40/17 street tire, doesn’t mean that is the case for a 15” version or for a drag tire (truck tire… whatever). Most soft, 28” tall or so drag tires in about that width will even work well on a 7” rim, and that 10” rim that you might mount a low profile setup intended for handling cold be too wide for the same width drag tire. And that’s even assuming that they’re the same width. For example, a 275 50 15 drag tire was originally designed to race a specific class were that tire was allowed to be quite a bit wider than any 275/50/15 really should be, so if you compare most of them to a 275/60 15 drag tire it will be significantly wider. For some tires that means you need a wider rim, but in some cases that wider tire was specifically designed with a sidewall and tread construction to deal with a smaller rim.

So what should you run? Well, look it up, there are tire charts available online and at any decent dealer showing the recommended range of rim sizes for a tire size. You’ll also find that people have tried a lot of combinations and you should be able to find documentation by doing a quick web search. There’s a few oddball older drag tires that will surprise you here, like BFG DR 275/50/15’s work surprisingly well on a 15x7 and M&H racemaster 305/40/16’s work great on 16x8” rims. Both look absolutely ridiculous, but there are plenty of people that have run these combinations at least into the low 1.5 60’ range…

FWIW, for a hard launching car too narrow a rim first results in a tire that likes to squirm at the top end, and then the fine line between the lower tire pressure needed to spread the bead out and where you don’t have enough pressure to keep it secure on the rim/support the tread is next. Too wide a rim will require too much air pressure too keep the tread flat and working and will decrease the amount of energy the tire can absorb.

To be honest, it’s quite common to run a 15x10” wheel on a 3rd gen, and I don’t really believe that without tubbing the rear of these cars can you get enough tire inside the back wheel wells to make up for the extra weight of the 10” rim with extra traction over an 8, 8.5 or 9” rim. If you’re just going to run a 275/60/15 on the back or other similar sized tire, get some 15x8’s and save yourself the weight and gain a little sidewall “give.”

joshh44

i dont have the stock wheels on my car. anyways i measured my rim from the inner beads of the rim and it came out to 8". as i was thinking about it for the last few days. i think a 10" wide would be pushing it. i forgot to count abit of the buldge on the sidewalls of the tire when its up to tire presure. i think a 9" would probaly suit what im going to be using the car for.

i dont really want to go 16" rims i like the size of 15s but it seems more cars these days are using 16" and its getting alittle harder to find tires for 15" rims with the size i want with out having to order them online.

83 Crossfire TA

iTrader: (2)

I’m with you there Josh…

FWIW, I’ve run my drag tires on stock 7”, 8” and 9” rims, and haven’t bothered with 10” rims. Right now I’m using a pair of 3.5” front and 9” rear draglites for the dragstrip.

If I had it my way I’d be running big 15” wheels on all 4 on the street/road course/autox if I could get a proper performance tire in a size appropriate to the car, since they would be lighter for the same tread surface, easier to drive at the limit, more durable, and cheaper. But the thing is that a good, large 15” performance tire doesn’t exist anymore, as a matter of fact, past a 205/50/15 I don’t know of a tire that can really be considered a real performance tire. You can get large tires in sort of sporty compounds like BFG radial TA’s and the comparable yokohamas…, but they’re not a real performance tire. For autox you can get some decent sizes that will work at least at moderate speed by running DR’s on all 4.

As it stands, the real serious performance tires that are coming out in large sizes now are 18’s, with some older and smaller models in 17’s, so I finally gave in and went with Z06 wheels (17x9 F and 18x10.5 rear) on my car for the street/handling…

joshh44

yeah if i wanted some good all around preformence tires that will glue me to the road. ill get different rims.
i want to get a set of C6 rims. but i would use that for crusing around and going to car shows and what not. and ill stick on the 15" for dragraing and or just for somthing different for the day. only takes afew mins to change a wheel on a car.
i was going to run a thinner tire up front for drag racing. but i think ill just get some skinnys up front insted and use the 15s that i have already for the rear. get 4 drag tires. and ill have an extra set of rear tires once the other set is worn out.

GodSpeedGTA

iTrader: (1)

And here everyone comes telling you that they run them on their car or bigger and have no problems etc. As was said, yes they will fit but it doesnt make it right. The blimping action that was mentioned is the way that the tire puffs over the rim edge and the sidewall isnt even closely aligned with the rim edge. Your street tires are not supposed to look like M/T drag slicks. You know when you see POS rides where they throw 22s on with the lowest possible rubberband sidewall tire on and the tire BARELY fits the rim.

Looks like this ./TTTT\. (the periods being the rim edges) Thats the same thing but in the opposite way. It works but its not right for the rim or the car.

IMHO, 245 50 16s look fantastic on my 16x8 GTA wheels when i had them on my car. They fit and look just right. I wont tell you or anybody else that if you put the 275s on or bigger that they will have problems or blowout because I highly doubt they will but I will tell you that its not right.

92RS702

I have 245/50/16 front and rear,the wheels are stock,I am going to put 255 on the rear soon that's as wide as you want to go,I think 255 will rub on the front,like GoodSpeed says 245s look nice on these cars,anything wider than a 255 on a 8 inch rim just doesn't look right.

230 firebird

I think yall have answered have answered my question without even knowing it.you guys are putting some decent rubber on these cars.I just wanted to know if i could switch from 15x7s to 17x8s with 245/45/17 all the way around without no rubbing problems.Some have said they will work and others didn't know,but after reading some of these replies,i think I will get on the phone and order my new rims and tires now.thanks to ALL

Stephen

iTrader: (12)

Go crazy...I've seen 335s on the FRONT, in autocross, so you can't say a car can't even turn with that wide of front tires! Delicate selection of backspacing is the key!

230 firebird

Thanks for the info.I'll stick with the 245s.For what its worth,the picture and insanity quote are cool.